Always the expression given within parenthesis is converted first. Since there are 2 expressions with the parenthesis, I am going with the expression (E + F + G) first, the order does not matter.

In the expression (E + F + G), there are 3 operands E,F and G and two operators, both being +. Since both the operators are the same, the expression is going to be evaluated from left to right. So E + F is considered first and converted into postfix form which is EF+. So, the expression becomes,

( ( A + B ) * C + D) / ([E F +] + G)

Any expression converted into postfix form is going to be written in square brackets.